The interactive element “select” must not
appear as a descendant of the “a” element.

The interactive element “select” must not
appear as a descendant of the “button” element.

Any “select” element descendant of a “label” element
with a “for” attribute must have an
ID value that matches that “for” attribute.

The “select” element cannot have more than one
selected “option” element descendant unless the
“multiple” attribute is specified.

A “select” element with
a “required” attribute and without
a “multiple” attribute, and whose
size is “1”, must have a child
“option” element.

The first child “option” element
of a “select” element with
a “required” attribute and without
a “multiple” attribute, and whose
size is “1”, must have either an
empty “value” attribute, or must
have no text content.